Advertisement

Advertisement

Japanese spacecraft launches to study Moon’s origin

Japan’s Kaguya spacecraft, in cooperation with its two helper satellites, will investigate the Moon’s origins (Illustration: JAXA)

A Japanese spacecraft carrying two ‘baby’ probes launched into space on Friday. Called Kaguya, it will be the most advanced spacecraft sent to the Moon since the Apollo missions in the 1970s.

Formerly known as SELENE, for SELenological and ENgineering Explorer, Kaguya is named after a character from a Japanese legend who travels to the Moon. It blasted off aboard an H-IIA rocket at 1031 JST (0131 GMT) from the Tanegashima Space Centre in Japan.

The spacecraft is designed to release two small 50-kilogram probes into their own orbits around the Moon. The trajectories of all three craft will be precisely measured to build up a detailed map of the Moon’s gravity field.

The main spacecraft is equipped with a wide variety of instruments, including ground-penetrating radar that will investigate the Moon’s structure down to a few kilometres below the surface.

Advertisement

Spectrometers will reveal the distribution of minerals on the Moon’s surface, a laser altimeter will map its topography and a high-resolution camera will image its surface in detail. A high-definition television camera will capture movies of the Earth rising above the Moon’s horizon to send back to Earth.

Scientists hope that data obtained by Kaguya will provide a better understanding of its origins. The leading theory is that the Moon formed from debris launched into space when a Mars-sized object crashed into the Earth about 4.5 billion years ago.

Popular destination

By studying the Moon’s “elemental composition, internal construction, differences in geographical features on both sides, the transition from the molten state that is assumed to have happened after its birth, and its volcanic history . . . it is hoped we can get closer to the core of the mystery of the origin and evolution of the Moon”, says Kaguya project manager Yoshisada Takizawa.

But this is not the first Japanese spacecraft to visit the Moon. Japan sent a smaller probe called Hiten, or Muses-A, to the Moon in the early 1990s, mainly to demonstrate spacecraft navigation technology. It orbited the Moon before it was intentionally crashed on the lunar surface in 1993.

And it is only one of a fleet of robotic craft set to fly to the Moon within the next year. China’s Chang’e 1 lunar orbiter is expected to launch in late 2007 (see China gears up to launch first lunar orbiter). It will include a stereo camera, an altimeter, a microwave instrument to measure the depth of lunar soil, and other instruments.

India’s Chandrayaan-1 lunar orbiter is scheduled to launch in May 2008. It is equipped with radar to search for water near the Moon’s poles and spectrometers to map the distribution of minerals on the lunar surface.

NASA’s Lunar Reconnaissance Orbiter is scheduled to launch in October 2008. It will include a high-resolution camera to map the surface and an ultraviolet instrument to search for surface ice and frost, among other instruments.